Plug and jack keepers



United States Patent i PLUG AND JACK KEEPERS Jack A. Meeker, Seattle, Wash, assignor to Boeing Airplane Company, Seattle, Wash., a corporation of Delaware Application November 19, 1954, Serial No. 470,009

Claims. (Cl. 339-61) The present invention relates to keepers for retaining in engagement an electrical plug and jack or equivalent interfitting elements.

The particular object is to provide such a keeper which will automatically be engaged in holding position whenever the plug and jack are fully interengaged. An incidental object is to enable full engagement of a plug and jack to be detected readily by the resistance to their separation effected by the keeper, whereas such resistance is absent or much less noticeable if the plug and jack are not fully interfitted.

A further object is to provide such a keeper which is of simple and inexpensive construction, yet which is very effective.

An additional object is to make such a keeper of extremely durable, yet light construction and which can be adapted easily for use on plugs and jacks of difierent types.

Another object is to construct a plug and jack keeper so that it also will serve to shield partly or completely contact prongs of the plug.

An important object is to enable such a keeper to be rendered operative without requiring any manipulation other than simply the complete engagement of the plug and jack. Consequently, no lost motion or lost time is involved in engaging or disengaging the keeper. When engaged, however, the keeper will be effective to prevent any inadvertent separation of the plug and jack.

While the keeper construction may be of different types, the foregoing objects can be accomplished by providing on one of the plug and jack elements a cup having an inturned rim and on the other element an annular rib, the outer periphery of which is slightly larger than the inner periphery of the cup rim. The rib, or the rim, is made of material sufliciently pliant and resilient so that the rib and rim may be moved axially past each other to dispose the rib in holding position behind the cup rim while the rib or rim or both return to their undeflected relaxed positions to resist axial separating movement of the jack and plug.

A typical example of keeper construction employing the principles of the present invention is shown in the accompanying drawings and described in the following detailed description.

Figure 1 is a longitudinal sectional view through a plug and jack, parts being shown in elevation, and the plug and jack being shown in registering but separated condition.

Figure 2 is a corresponding longitudinal sectional view through the plug and jack shown in fully engaged relationship.

Figure 3 is an exploded view of the plug and jack parts in perspective with portions of certain parts being broken away.

The plug and jack to which the keeper of the present invention is applied may be of conventional construction. Thus the plug may include any number of prongs 1 embedded in and projecting from a base 10. This base may include a boss 11 threaded to receive on it an internally threaded nut or cap 12. A cup 13 of a size ice bottom may be clampedbetween the base It and cap 12 by screwing the cap tightly onto the threaded boss 11 in the manner shown in Figure 1.

The jack also may incorporate a base 2 apertured in a pattern corresponding to the arrangement of the prongs 1 to receive such prongs as the bases 2 and 10 are moved axially toward each other. The base 2 also preferably has an externally threaded boss projecting from its side opposite that through which the jack sockets open. The sockets extend lengthwise through this boss and metal linings in them may be connected respectively to connecting wire soldering lugs 21 projecting from the end of the boss 20 opposite the base 2.

The jack element has a radial projection 22 preferably in the form of a circumferential rib. In the type of construction illustrated in the drawings this projection or rib is located adjacent to the side of base 2 opposite that in which the jack sockets open and is formed by a washer having an aperture of a size to fit reasonably snugly over the external threads of boss 20. This washer can be secured in place against the adjacent face of base 2 by a cap 23 having one end threaded internally to screw onto the threads of boss 20. The opposite end of this cap has an aperture 24 for receiving wires connected to the soldering lug 21. i

The interior of cup 13 is of a size to receive the radial jack members are pushed into engagement it is necessary that either the cup member or the projection member, or both, be yieldable. It is further desirable that the material of which the yieldable member is made be sufliciently resilient so that when the plug and jack members have been moved into interfitting engagement as shown in Figure 2, the yieldable member will have returned substantially to its unstressed condition.

A convenient construction is to form the cup, or at least its inwardly projecting flanged rim, of a somewhat yieldable, tough plastic material such as the plastics sold under the names nylon, Teflon or polyethylene. Besides being resilient to a reasonable degree, these plastic materials are good electric insulators. Alternatively, rubber or synthetic rubber could be used of a type having slightly yielding characteristics. All of such materials may be designated as slightly resilient plastic material.

If the entire cup 13 and rim 15 are made of a slightly resilient plastic material, the diameter of the rib 22 should be from one-thousandth to fifteen-thousandths of an inch larger than the internal diameter of the rim 15, depending upon the degree of resilience of the ma terial of which the cup is made, and how tightly it is desired to have the parts held together. For ease of engagement and disengagement of the rib and rim, it is preferred that the periphery of the rib be somewhat rounded as shown best in Figure 1, although as an alternative or in addition the inner edgeof the cup rim 15 could be roundted. Alternatively, either the rim or the rib could be slightly inclined to facilitate engagement of the rib with the rim without reducing the efiort required to I Figure 2.

While the cup memberis shown as being mounted on the plug and the-projection or ribprovided on thejack, it will be evident that the cup and rib elements could be provided on thejack and plug members, respectively. Particularlywhere the cup is formed as, a separate part, as shown in Figure 3, and the rib is formed by the outer periphery of-a separate washer, such its-22, shown ll] Figure 3, these parts may, be designed to fit interchangeably on either the plug or the jack. Alternatively, however, the cup and projection or ribcould' be formed asintegral parts of the plug and jack members.

Furthermore, while the keeper construction described above has been illustrated as applied-to cooperating plug and jack members, keeper construction of this type could be utilized'to retain in engagement cooperating members of other types, and the-keeper,elernentscould be engagedeither by direct approach movement or by, such movement accompanied by rotation. Members with which the keeper construction described could be used may be designated generally as members interengageable by approach movement whether or not rotation accompanies such approach-movement.

I claim as my invention:

1. Keeper mechanism comprising members 'i'nterengageableby approach, movement and each having a base and athreaded boss projecting from said'base, capmeans having an aperture in'its'bottom received on one of said threaded bosses with the sides of said cup element, encircling the base of said one boss, having an inwardly flanged rim and having threads screwed ,on'such one boss securing said cup means-thereto, means having an annular rib and an apertureyreceived onthej other of said threaded bosses, having an outer periphery of a size great enough so as not to pass, the inwardly'fianged rim of said cup means without deformationandh'aving threads screwed on such otherboss securing saidjannular rib means thereto, the depth of saidcup meansibeing suificiently great so that its .rim interferes withfthe, circumference of said annular. rib: as the'basesof-said members are moved, toward eachother andpriortotheifr abutment, andoneof said meansibeing sufficient ly yieldable toenable said annular rib andthe inwardly;flange,d rim of said cup means to pass in one direction during ap proach movement of said-members'into-full eng l menh and being sufficiently resilient to create substantial resistance to separation of said members which requires,

said annular rib and;the"rim of said cup means to pass in'the opposite direction.

2. Keeper mechanism comprising ,men lbers' i'nterengageable by approach movement and eachjhavingabase and a threaded boss projectingfrom said base, a cup element having an aperturein'its'bottom received on one of said threaded bosses ,with the sides of *said cup ,element encircling,the'base of said one boss and having an inwardly flanged rim, a threadedcap screwedcn such one boss and clamping said cup element, awasher element received on the other of said threaded bosses and having an'outer periphery of,a size great,enough so.as not to pass the inwardly flanged rimofxsaid cup element without deformation, and a capthreaded onsuch other boss and operableto clamp saidlwasherelement,

the depth of said cup element beingsufiiciently great so that its inwardlyflanged'rim interferes'withthe circumference of said washer elementas thebasesof said members are moved toward each other and prior to theirabutment, and one of said elementsbeing sufiiciently yieldable to enable said washer element and the rim of said cup element'to pass in onedirection during approach-movement of ;said members into full engagement, and being sufiiciently resilient to createsubstantialresistance to separation of said'members'which requires said washer element and the inwardly 1 flanged rim; of said cup element to 7 pass in the opposite fdirection;

f3. Keeper mechanism -comprising members intere ngageable byapproach movement l and each having a base and a threaded boss projecting from said base, a cup element having an aperture-in its bottom received on one of said threaded bosses with the sides of said cup element of slightly resilient plastic material encircling the base of said one boss and having an inwardly flanged rim, a threaded cap screwedon such one boss and clamping said cup element,va washer element received on the other of said threaded bosses and having an outer peripheryvof a size great-enough, so as not to pass the inwardly flanged rim. of said. cup. element, without deformation of its rim, and a cap threaded on such other boss and operable to, clampcsaidlwasher element, the depth of said cup element being sufiiciently great so that its inwardly flanged rim interfieres ,Wlihiihfl circumference of said washer element as the bases of said members are moved toward each other and prior to their abutment,

and said, cup element'being ,suifici'ently yieldable to enable said was her elementand the rim of said cup element to pass in one direction during approach movement of said members into, full engagemenhand being sufficiently resilient to create substantial resistance to separation ofsaid'members which, requires said washer element and the inwardly flanged rim of said cup element to pass in the opposite direction.

4. Keeper mechanism comprising a plug member having a threaded boss, a jack member having a threaded boss, a cup having anlaperture in itsbottom received on one of saidthreadedbosses and including an inwardly flanged rim, said cup being of slightly resilient plastic material, a threaded cap screwed ontsaid, cup-receiving boss andclamping said cup inplace, a washer received on the other of said threadedbosses andhaVing an outer periphery of a size great enough so as not to pass the inwardly flangedrim ofv said cup withoutdef ormation, and a cap threaded on said washer-receivingboss and operable to clamp said washer in place in a position to cause saidwasher tointerfere with the inwardly flanged rim of said cup during approach movement of sai'djplug and jack members into full interengagement, ,said cup being yieldable to pass the-periphery of said Washerduring approach movement of said plug and jackmembers into full interengagement, andthe resiliencetofisaid cup creating substantial resistance to separation .015 said plug and jack members during separation thereof which requires said cup and washer to pass, in the opposite direction.

5. Keeper mechanism comprising a plug member including.Prongs andhaving athreaded boss, a jack member haying a threaded boss,- acup havinganaperture in its bottom received, on the threaded boss ofsaid plug member and including a side wall encirclingsaid prongs. and an inwardly flangedrim, said cup vbeingof slightly resilient plastic material, a threaded cap screwedvon said plug member boss and clamping said cup in place, a washer received on thethreaded bossvof saidjack memher and having an outer periphery of a size .greatenough soasnnotto pass the inwardly flanged rim of said cup without deformation, and a cap threaded on said jack membergboss andoperable. to clamp said washerin place in a position to cause said Washer to interfere With the,

inwardlyflangedrim of said cup during approach movement of saidpIug-and jack members into full interengagement, said ;cup:being yieldable to pass the periphery vof said washer during approach movement of said plug References Cited in the file of this patent FOREIGN PATENTS 405,773- Great-Britain Feb. 15, 1934 490,013 Great'Britain Aug. 5,1938 1,011,629 France Apr. 2, 1952 

